openapi-generator: [BUG][Kotlin] With version 4.1.1 I cannot build my kotlin server stubs anymore, was working with 4.1.0

Bug Report Checklist

• What’s the version of OpenAPI Generator used? 4.1.1

Description

I am using the openapi gradle plugin. If I switch to version 4.1.1, it stops working with unknown error. I have to rollback the version to 4.1.0 to make it work again. The yaml file is validated automatically via gradle. I get this exception when trying to generate the server stubs:

`FAILURE: Build failed with an exception.

• What went wrong: Execution failed for task ‘:buildKotlinServer’.

java.lang.UnsupportedOperationException (no error message)

• Try: Run with --info or --debug option to get more log output. Run with --scan to get full insights.

• Exception is: org.gradle.api.tasks.TaskExecutionException: Execution failed for task ‘:buildKotlinServer’. at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$3.accept(ExecuteActionsTaskExecuter.java:166) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$3.accept(ExecuteActionsTaskExecuter.java:163) at org.gradle.internal.Try$Failure.ifSuccessfulOrElse(Try.java:191) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:156) at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:62) at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:108) at org.gradle.api.internal.tasks.execution.ResolveBeforeExecutionOutputsTaskExecuter.execute(ResolveBeforeExecutionOutputsTaskExecuter.java:67) at org.gradle.api.internal.tasks.execution.StartSnapshotTaskInputsBuildOperationTaskExecuter.execute(StartSnapshotTaskInputsBuildOperationTaskExecuter.java:62) at org.gradle.api.internal.tasks.execution.ResolveAfterPreviousExecutionStateTaskExecuter.execute(ResolveAfterPreviousExecutionStateTaskExecuter.java:46) at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:94) at org.gradle.api.internal.tasks.execution.FinalizePropertiesTaskExecuter.execute(FinalizePropertiesTaskExecuter.java:46) at org.gradle.api.internal.tasks.execution.ResolveTaskExecutionModeExecuter.execute(ResolveTaskExecutionModeExecuter.java:95) at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:57) at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:56) at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:36) at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.executeTask(EventFiringTaskExecuter.java:77) at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:55) at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:52) at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:416) at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:406) at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:165) at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250) at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158) at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:102) at org.gradle.internal.operations.DelegatingBuildOperationExecutor.call(DelegatingBuildOperationExecutor.java:36) at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:52) at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:43) at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:355) at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:343) at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:336) at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:322) at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker$1.execute(DefaultPlanExecutor.java:134) at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker$1.execute(DefaultPlanExecutor.java:129) at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:202) at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.executeNextNode(DefaultPlanExecutor.java:193) at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:129) at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64) at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:48) at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56) Caused by: java.lang.UnsupportedOperationException at com.google.common.collect.ImmutableMap.put(ImmutableMap.java:450) at org.openapitools.codegen.config.WorkflowSettings$Builder.withSystemProperty(WorkflowSettings.java:465) at org.openapitools.codegen.config.CodegenConfigurator.addSystemProperty(CodegenConfigurator.java:141) at org.openapitools.generator.gradle.plugin.tasks.GenerateTask.doWork(GenerateTask.kt:398) at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:103) at org.gradle.api.internal.project.taskfactory.StandardTaskAction.doExecute(StandardTaskAction.java:49) at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:42) at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:28) at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:717) at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:684) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$5.run(ExecuteActionsTaskExecuter.java:476) at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:402) at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:394) at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:165) at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250) at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158) at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:92) at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:461) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:444) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.access$200(ExecuteActionsTaskExecuter.java:93) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$TaskExecution.execute(ExecuteActionsTaskExecuter.java:237) at org.gradle.internal.execution.steps.ExecuteStep.lambda$execute$1(ExecuteStep.java:33) at org.gradle.internal.execution.steps.ExecuteStep.execute(ExecuteStep.java:33) at org.gradle.internal.execution.steps.ExecuteStep.execute(ExecuteStep.java:26) at org.gradle.internal.execution.steps.CleanupOutputsStep.execute(CleanupOutputsStep.java:58) at org.gradle.internal.execution.steps.CleanupOutputsStep.execute(CleanupOutputsStep.java:35) at org.gradle.internal.execution.steps.ResolveInputChangesStep.execute(ResolveInputChangesStep.java:48) at org.gradle.internal.execution.steps.ResolveInputChangesStep.execute(ResolveInputChangesStep.java:33) at org.gradle.internal.execution.steps.CancelExecutionStep.execute(CancelExecutionStep.java:39) at org.gradle.internal.execution.steps.TimeoutStep.executeWithoutTimeout(TimeoutStep.java:73) at org.gradle.internal.execution.steps.TimeoutStep.execute(TimeoutStep.java:54) at org.gradle.internal.execution.steps.CatchExceptionStep.execute(CatchExceptionStep.java:35) at org.gradle.internal.execution.steps.CreateOutputsStep.execute(CreateOutputsStep.java:51) at org.gradle.internal.execution.steps.SnapshotOutputsStep.execute(SnapshotOutputsStep.java:45) at org.gradle.internal.execution.steps.SnapshotOutputsStep.execute(SnapshotOutputsStep.java:31) at org.gradle.internal.execution.steps.CacheStep.executeWithoutCache(CacheStep.java:208) at org.gradle.internal.execution.steps.CacheStep.execute(CacheStep.java:70) at org.gradle.internal.execution.steps.CacheStep.execute(CacheStep.java:45) at org.gradle.internal.execution.steps.BroadcastChangingOutputsStep.execute(BroadcastChangingOutputsStep.java:49) at org.gradle.internal.execution.steps.StoreSnapshotsStep.execute(StoreSnapshotsStep.java:43) at org.gradle.internal.execution.steps.StoreSnapshotsStep.execute(StoreSnapshotsStep.java:32) at org.gradle.internal.execution.steps.RecordOutputsStep.execute(RecordOutputsStep.java:38) at org.gradle.internal.execution.steps.RecordOutputsStep.execute(RecordOutputsStep.java:24) at org.gradle.internal.execution.steps.SkipUpToDateStep.executeBecause(SkipUpToDateStep.java:96) at org.gradle.internal.execution.steps.SkipUpToDateStep.lambda$execute$0(SkipUpToDateStep.java:89) at org.gradle.internal.execution.steps.SkipUpToDateStep.execute(SkipUpToDateStep.java:54) at org.gradle.internal.execution.steps.SkipUpToDateStep.execute(SkipUpToDateStep.java:38) at org.gradle.internal.execution.steps.ResolveChangesStep.execute(ResolveChangesStep.java:76) at org.gradle.internal.execution.steps.ResolveChangesStep.execute(ResolveChangesStep.java:37) at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsFinishedStep.execute(MarkSnapshottingInputsFinishedStep.java:36) at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsFinishedStep.execute(MarkSnapshottingInputsFinishedStep.java:26) at org.gradle.internal.execution.steps.ResolveCachingStateStep.execute(ResolveCachingStateStep.java:90) at org.gradle.internal.execution.steps.ResolveCachingStateStep.execute(ResolveCachingStateStep.java:48) at org.gradle.internal.execution.steps.CaptureStateBeforeExecutionStep.execute(CaptureStateBeforeExecutionStep.java:69) at org.gradle.internal.execution.steps.CaptureStateBeforeExecutionStep.execute(CaptureStateBeforeExecutionStep.java:47) at org.gradle.internal.execution.impl.DefaultWorkExecutor.execute(DefaultWorkExecutor.java:33) at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:140) … 35 more `

openapi-generator version

4.1.1

OpenAPI declaration file content or url

Just use the standard Pet API yaml

Command line used for generation

Kotlin server config file server-api-config.json

{ "sourceFolder" : "", "packageName" : "com.xxx.yyy.api.autogenerated", "groupId": "com.xxx.yyy.api", "featureCors" : false, "featureAutoHead" : false, "featureConditionalHeaders" : false, "featureHSTS" : false, "featureCompression" : false }

Steps to reproduce

gradle task used:

task buildKotlinServer(type: org.openapitools.generator.gradle.plugin.tasks.GenerateTask) {
    generatorName = "kotlin-server"
    inputSpec = "$stageDir/docs/api.yaml"
    outputDir = "$srcDir/main/kotlin"
    templateDir = "$srcDir/main/mustache/kotlin-server"
    configFile = "$rootDir/server-api-config.json"
    supportingFilesConstrainedTo = [
            "Paths.kt"
    ]
    systemProperties = [
            models: "",
            apis  : "",
    ]
}